Concrete pump s tube, Concrete pump s pipe, Concrete pump s valve S valve is constructed of the plate, flanges, and splined shafts that have been joined together through welding. The splined shaft is made of 38CrMoAI, which has become a preferred choice for manufacturers in making concrete pump S tube. Chrome-plated shaft sleeves are made of #45 seamless carbon steel tube,with the chrome plating thickness between 0.12mm and 0.16mm. The inner hole of the s-shaped tube valve is welded up by wear-resistant welding electrode. Material Welded pipe 16Mn, Shaft 38CrMoAl,